Two Iraqi men have been arrested in the German capital on suspicion of membership in a terrorist organization and war crimes as part of the Islamic State group, federal prosecutors said Tuesday.

A 31-year-old, identified only as Raad Riyadh A. A. in line with privacy laws, and 19-year-old Abbas R. were both arrested Monday in Berlin, prosecutors' spokeswoman Frauke Koehler said. They're both alleged to have joined IS in Mosul in June 2014 and participated in the killing of two Shiite Muslims.

Four months later, prosecutors said, they were involved in the execution of a captured Iraqi military officer.

While in Iraq, Raad Riyadh A.A. is also accused of extorting money from businesses to support IS and procuring weapons from the Iraqi army and police forces for the group.

After arriving in Germany in July 2015, Raad Riyadh A.A. tried to recruit two other Iraqis and convince a third to carry out a suicide attack, Koehler said.

In a separate case, a 24-year-old Syrian was arrested in the northern state of Schleswig-Holstein on allegations he was a member of multiple foreign terrorist organizations, including IS. Majed A. was arrested Sept. 13 and is also accused of weapons violations.

In 2013, he joined a militia affiliated with the Nusra Front group in Syria to fight against the Assad regime, Koehler said. He ended up with IS in 2014 and fought against Kurdish forces in northern Syria before entering in Germany in August 2015.